Agriculture Reference
In-Depth Information
identify the presence of a compound. In addition, they did not observe any signi
cant
MS
n
compared
differences in the absolute intensity of fragment ions when using SRM
-
with full scan MS
n
. However, they highlighted that both SRM
MS
n
and full scan MS
n
required previous knowledge of possible analytes present in the sample in order to set
instrument parameters for the detection of those analytes. Gallo et al. [66] proposed an
HPLC
-
rmatory analysis of moenomycin A in feed. The
analysis was performed using SRMmode and proved to be highly selective and reliable
for unambiguous identi
-
IT
-
MS/MS method for con
cation of moenomycin A (Table 6.3).
The capability of the MS
n
acquisition mode to characterize and study fragmenta-
tion patterns of the major components of moenomycin was shown by Eichhorn
et al. [112]. In this work,
five moenomycins (A, A
12
,C
1
,C
3
, and C
4
) isolated from a
commercial chicken feed were chromatographically separated and identi
ed, and
their fragmentation patterns were explored using IT
-
MS employing full scan MS,
MS
2
, and MS
3
.
6.4.3 Comparison Studies
The relatively recent use of HRMS techniques and their successful applications
reported in the
field of food safety has provoked their unavoidable comparison with
traditional LRMS techniques. Some comparative studies on the performance of
LRMS and HRMS analyzers, such as QqQ
-
MS and TOF
-
MS, QqTOF
-
MS, and
Orbitrap
-
MS, have been developed. One of the
first studies was developed by Gentili
et al. [101], which compared HPLC
-
QqQ
-
MS/MS and HPLC
-
QqTOF
-
MS/MS
systems in terms of sensitivity and speci
city for the analysis of six hormones in meat
and baby food. The results showed that the QqQ
-
MS/MS achieved at least 20-fold
higher sensitivity compared with the QqTOF
MS/MS instrument for almost all of the
analytes that were studied. Nevertheless, in terms of selectivity, QqTOF
-
-
MS/MS
offered the highest performance. Additionally, the low values of CC
α
and CC
β
obtained with HPLC
MS/MS system for all the analytes in meat demonstrated
its applicability to satisfying the MRPLs of anabolic agents (1
-
QqQ
-
μ
g/kg for the analyzed
anabolic agents, except for zeranol proposed at 2
μ
g/kg), while HPLC
-
QqTOF
-
MS/
MS did not satisfy these conditions, obtaining CC
β
>
1
μ
g/kg. Subsequently, Wang
et al. [65] compared UHPLC
-
QqTOF
-
MS and HPLC
-
QqQ
-
MS/MS for quanti
ca-
tion and identi
cation of six macrolides and degradation products in eggs, milk, and
honey. Both techniques demonstrated suitable quantitative performance in terms of
trueness (the closeness of agreement between the average value obtained from a large
series of test results and an accepted reference value) and repeatability. However,
LODs obtained with the UHPLC
-
QqTOF
-
MS method (0.2
-
1.0
μ
g/kg) were higher
than those obtained with the HPLC
g/kg), demonstrating
the higher sensitivity of this technique in comparison with the HRMS instrument
used. On the other hand, UHPLC
-
QqQ
-
MS/MS (0.01
-
0.5
μ
-
QqTOF
-
MS provided unambiguous con
rmation
of positive
cation of degradation products based on accurate
mass measurements. This was tested by the identi
findings and the identi
cation of tylosin B, a degradation
product of tylosin A in honey samples, which cannot be purchased from commercial
sources. As a result of this work,
the authors considered both techniques as
